51 lines
1.5 KiB
Java
51 lines
1.5 KiB
Java
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/*
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Calculate Circle Area using Java Example
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This Calculate Circle Area using Java Example shows how to calculate
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area of circle using it's radius.
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*/
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import java.io.BufferedReader;
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import java.io.IOException;
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import java.io.InputStreamReader;
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public class CalculateCircleAreaExample
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{
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public static void main(String[] args)
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{
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int radius = 0;
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System.out.println("Please enter radius of a circle");
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try
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{
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//get the radius from console
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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radius = Integer.parseInt(br.readLine());
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}
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//if invalid value was entered
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catch(NumberFormatException ne)
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{
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System.out.println("Invalid radius value" + ne);
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System.exit(0);
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}
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catch(IOException ioe)
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{
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System.out.println("IO Error :" + ioe);
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System.exit(0);
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}
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/*
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* Area of a circle is
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* pi * r * r
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* where r is a radius of a circle.
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*/
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//NOTE : use Math.PI constant to get value of pi
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double area = Math.PI * radius * radius;
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System.out.println("Area of a circle is " + area);
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}
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}
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/*
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Output of Calculate Circle Area using Java Example would be
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Please enter radius of a circle
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19
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Area of a circle is 1134.1149479459152
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*/
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